New Western air strikes in Syria would provoke “chaos” in international relations, Russian President Vladimir Putin told his Iranian counterpart Hassan Rowhani on Sunday.

Speaking to Rowhani by telephone the day after US-led strikes on suspected chemical weapons facilities, Putin said “if such actions, carried out in violation of the United Nations Charter, are repeated, that would inevitably provoke chaos in international relations,” according to a statement from the Kremlin.

The two leaders “found that this illegal action seriously damaged the prospects of a political settlement in Syria,” the statement said.

The United States, France and Britain on Saturday launched strikes against Bashar al-Assad’s government a week after an alleged chemical attack in the Syrian city of Douma, just east of the capital Damascus.

Putin denounced on Saturday “with the utmost firmness” the strikes which he described as “an act of aggression against a sovereign state which is at the forefront of the fight against terrorism”.

Meanwhile, the US Treasury Department will announce fresh sanctions on Monday on Russia related to its involvement in Syria’s use of chemical weapons, US United Nations Ambassador Nikki Haley said on Sunday.

“Russian sanctions will be coming down, Secretary Mnuchin will be announcing those Monday if he hasn’t already and they will have to do with chemical equipment used by Assad,” Haley said on CBS’s Face the Nation, referring to Treasury Secretary Steven Mnuchin.

The US has previously expelled Russian diplomats and sanctioned Russia, a Syrian ally, for a suspected nerve agent attack against a former spy in Britain and other actions.